﻿#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>


int Add(int x, int y)
{
	return x + y;
}
int Sub (int x, int y)
{
	return x - y;
}
int main()
{
	

	int(* pfArr[2])(int, int) = { Add,Sub };
	return 0;
}



int add(int a, int b)
{
	return a + b;
}
int sub(int a, int b)
{
	return a - b;
}
int mul(int a, int b)
{
	return a * b;
}
int div(int a, int b)
{
	return a / b;
}
int main()
{
	int x, y;
	int input = 1;
	int ret = 0;
	do
	{
		printf("*************************\n");
		printf(" 1:add 2:sub \n");
		printf(" 3:mul 4:div \n");
		printf(" 0:exit \n");
		printf("*************************\n");
		printf("请选择：");
		scanf("%d", &input);
		switch (input)
		{
		case 1:
			printf("输⼊操作数：");
			scanf("%d %d", &x, &y);
			ret = add(x, y);
			printf("ret = %d\n", ret);
			break;
		case 2:
			printf("输⼊操作数：");
			scanf("%d %d", &x, &y);
			ret = sub(x, y);
			printf("ret = %d\n", ret);
			break;
		case 3:
			printf("输⼊操作数：");
			scanf("%d %d", &x, &y);
			ret = mul(x, y);
			printf("ret = %d\n", ret);
			break;
		case 4:
			printf("输⼊操作数：");
			scanf("%d %d", &x, &y);
			ret = div(x, y);
			printf("ret = %d\n", ret);
			break;
		case 0:
			printf("退出程序\n");
			break;
		default:
			printf("选择错误\n");
			break;
		}
	} while (input);
	return 0;
}


//使用函数指针数组

int add(int a, int b)
{
	return a + b;
}
int sub(int a, int b)
{
	return a - b;
}
int mul(int a, int b)
{
	return a * b;
}
int div(int a, int b)
{
	return a / b;
}
	int main()
	{
		int x, y;
		int input = 1;
		int ret = 0;
		int(*p[5])(int x, int y) = { 0, add, sub, mul, div }; //转移表
		do
		{
			printf("*************************\n");
			printf(" 1:add 2:sub \n");
			printf(" 3:mul 4:div \n");
			printf(" 0:exit \n");
			printf("*************************\n");
			printf("请选择：");
			scanf("%d", &input);
			if ((input <= 4 && input >= 1))
			{
				printf("输⼊操作数：");
				scanf("%d %d", &x, &y);
				ret = (*p[input])(x, y);
				printf("ret = %d\n", ret);
			}
			else if (input == 0)
			{
				printf("退出计算器\n");
			}
			else
			{
				printf("输⼊有误\n");
			}
		} while (input);
			return 0;
	}